Add exception for ligand lookup during build_structures
Add exception for ligand lookup during build_structures

fosfataza/protwis,protwis/protwis,cmunk/protwis,fosfataza/protwis,cmunk/protwis,protwis/protwis,cmunk/protwis,cmunk/protwis,fosfataza/protwis,protwis/protwis,fosfataza/protwis